using System;
using System.Web;
using System.Configuration;
/// <summary>
/// Summary description for PublicMethod
/// </summary>
public class PublicMethod 
{
    public PublicMethod()
    {
    }
    //文件路径
    public static string ffmpegtool = ConfigurationSettings.AppSettings["ffmpeg"];
    public static string mencodertool = ConfigurationSettings.AppSettings["mencoder"];
    public static string mplayertool = ConfigurationSettings.AppSettings["mplayer"];
    public static string upFile = ConfigurationSettings.AppSettings["upfile"] + "/";
    public static string imgFile = ConfigurationSettings.AppSettings["imgfile"] + "/";
    public static string playFile = ConfigurationSettings.AppSettings["playfile"] + "/";
    //文件图片大小
    public static string sizeOfImg = ConfigurationSettings.AppSettings["CatchFlvImgSize"];
    //文件大小
    public static string widthOfFile = ConfigurationSettings.AppSettings["widthSize"];
    public static string heightOfFile = ConfigurationSettings.AppSettings["heightSize"];
    // // //获取文件的名字
    public static string GetFileName(string fileName)
    {
        int i = fileName.LastIndexOf("\\") + 1;
        string Name = fileName.Substring(i);
        return Name;
    }
    //获取文件扩展名
    public static string GetExtension(string fileName)
    {
        int i = fileName.LastIndexOf(".") + 1;
        string Name = fileName.Substring(i);
        return Name;
    }
    //
    #region //运行FFMpeg的视频解码，(这里是绝对路径)
    /// <summary>
    /// 转换文件并保存在指定文件夹下面(这里是绝对路径)
    /// </summary>
    /// <param name="fileName">上传视频文件的路径（原文件）</param>
    /// <param name="playFile">转换后的文件的路径（网络播放文件）</param>
    /// <param name="imgFile">从视频文件中抓取的图片路径</param>
    /// <returns>成功:返回图片虚拟地址; 失败:返回空字符串</returns>
    public string ChangeFilePhy(string fileName, string playFile, string imgFile)
    {
        //取得ffmpeg.exe的路径,路径配置在Web.Config中,如:<add key="ffmpeg" value="E:\51aspx\ffmpeg.exe" /> 
        //string ffmpeg = HttpContext.Current.Server.MapPath(PublicMethod.ffmpegtool);
        string ffmpeg = PublicMethod.ffmpegtool;
        if ((!System.IO.File.Exists(ffmpeg)) || (!System.IO.File.Exists(fileName)))
        {
            return "";
        }
        //获得图片和(.flv)文件相对路径/最后存储到数据库的路径,如:/Web/User1/00001.jpg 
        string flv_file = System.IO.Path.ChangeExtension(playFile, ".flv");

        //截图的尺寸大小,配置在Web.Config中,如:<add key="CatchFlvImgSize" value="240x180" /> 
        string FlvImgSize = PublicMethod.sizeOfImg;
        System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);
        //FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal;
        FilestartInfo.Arguments = " -i " + fileName + " -ab 56 -ar 22050 -b 500 -r 15 -s " + widthOfFile + "x" + heightOfFile + " " + flv_file;
        //ImgstartInfo.Arguments = " -i " + fileName + " -y -f image2 -t 0.05 -s " + FlvImgSize + " " + flv_img;
        try
        {
            //转换
            System.Diagnostics.Process.Start(FilestartInfo);
            //截图
            CatchImg(fileName, imgFile);
            //System.Diagnostics.Process.Start(ImgstartInfo);
        }
        catch
        {
            return "";
        }
        //
        return "";
    }
    //
    public string CatchImg(string fileName, string imgFile)
    {
        //
        //string ffmpeg = HttpContext.Current.Server.MapPath(PublicMethod.ffmpegtool);
        string ffmpeg = PublicMethod.ffmpegtool;
        //
        string flv_img = imgFile + ".jpg";
        //
        string FlvImgSize = PublicMethod.sizeOfImg;
        //
        System.Diagnostics.ProcessStartInfo ImgstartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);
        //ImgstartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        ImgstartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal;
        //
        ImgstartInfo.Arguments = " -i " + fileName + " -y -f image2 -ss 2 -vframes 1 -s " + FlvImgSize + " " + flv_img;
        try
        {
            System.Diagnostics.Process.Start(ImgstartInfo);
        }
        catch
        {
            return "";
        }
        //
        if (System.IO.File.Exists(flv_img))
        {
            return flv_img;
        }
        return "";
    }
    #endregion
    //
    #region //运行FFMpeg的视频解码，(这里是(虚拟)相对路径)
    /// <summary>
    /// 转换文件并保存在指定文件夹下面(这里是相对路径)
    /// </summary>
    /// <param name="fileName">上传视频文件的路径（原文件）</param>
    /// <param name="playFile">转换后的文件的路径（网络播放文件）</param>
    /// <param name="imgFile">从视频文件中抓取的图片路径</param>
    /// <returns>成功:返回图片虚拟地址; 失败:返回空字符串</returns>
    public string ChangeFileVir(string fileName, string playFile, string imgFile)
    {
        //取得ffmpeg.exe的路径,路径配置在Web.Config中
        //string ffmpeg = HttpContext.Current.Server.MapPath(PublicMethod.ffmpegtool);
        string ffmpeg = PublicMethod.ffmpegtool;
        if ((!System.IO.File.Exists(ffmpeg)) || (!System.IO.File.Exists(fileName)))
        {
            return "";
        }
        //获得图片和(.flv)文件相对路径/最后存储到数据库的路径,如:/Web/User1/00001.jpg 
        string flv_img = System.IO.Path.ChangeExtension(HttpContext.Current.Server.MapPath(imgFile), ".jpg");
        string flv_file = System.IO.Path.ChangeExtension(HttpContext.Current.Server.MapPath(playFile), ".flv");

        //截图的尺寸大小,配置在Web.Config中,如:<add key="CatchFlvImgSize" value="240x180" /> 
        string FlvImgSize = PublicMethod.sizeOfImg;
        System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);
        System.Diagnostics.ProcessStartInfo ImgstartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);
        FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        ImgstartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        //此处组合成ffmpeg.exe文件需要的参数即可,此处命令在ffmpeg 0.4.9调试通过 
        //ffmpeg -i F:\01.wmv -ab 56 -ar 22050 -b 500 -r 15 -s 320x240 f:\test.flv
        FilestartInfo.Arguments = " -i " + fileName + " -ab 56 -ar 22050 -b 500 -r 15 -s " + widthOfFile + "x" + heightOfFile + " " + flv_file;
        ImgstartInfo.Arguments = " -i " + fileName + " -y -f image2 -t 0.001 -s " + FlvImgSize + " " + flv_img;
        try
        {
            System.Diagnostics.Process.Start(FilestartInfo);
            System.Diagnostics.Process.Start(ImgstartInfo);
        }
        catch
        {
            return "";
        }
        /**/
        ///注意:图片截取成功后,数据由内存缓存写到磁盘需要时间较长,大概在3,4秒甚至更长; 
        ///这儿需要延时后再检测,我服务器延时8秒,即如果超过8秒图片仍不存在,认为截图失败; 
        ///此处略去延时代码.如有那位知道如何捕捉ffmpeg.exe截图失败消息,请告知,先谢过! 
        if (System.IO.File.Exists(flv_img))
        {
            return flv_img;
        }
        return "";
    }
    #endregion
    #region //运行mencoder的视频解码器转换(这里是(绝对路径))
    public string MChangeFilePhy(string vFileName, string playFile, string imgFile)
    {
        //string tool = HttpContext.Current.Server.MapPath(PublicMethod.mencodertool);
        string tool = PublicMethod.mencodertool;
        //string mplaytool = Server.MapPath(PublicMethod.ffmpegtool);
        if ((!System.IO.File.Exists(tool)) || (!System.IO.File.Exists(vFileName)))
        {
            return "";
        }
        string flv_file = System.IO.Path.ChangeExtension(playFile, ".flv");

        //截图的尺寸大小,配置在Web.Config中,如:<add key="CatchFlvImgSize" value="240x180" /> 
        string FlvImgSize = PublicMethod.sizeOfImg;
        System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(tool);
        FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        FilestartInfo.Arguments = " " + vFileName + " -o " + flv_file + " -of lavf -lavfoptsi_certify_that_my_video_stream_does_not_use_b_frames -oac mp3lame -lameopts abr:br=56 -ovc lavc -lavcopts vcodec=flv:vbitrate=200:mbd=2:mv0:trell:v4mv:cbp:last_pred=1:dia=-1:cmp=0:vb_strategy=1 -vf scale=" + widthOfFile + ":" + heightOfFile + " -ofps 12 -srate 22050";
        try
        {
            System.Diagnostics.Process.Start(FilestartInfo);
            CatchImg(flv_file, imgFile);
        }
        catch
        {
            return "";
        }
        //
        return "";
    }
    #endregion
}

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <!--工具文件夹-->
    <add key="ffmpeg" value="D:\STUDY\dotnet项目\ToFlv\ToFlv\ffmpeg\ffmpeg.exe"/>
    <add key="mencoder" value="D:\STUDY\dotnet项目\ToFlv\ToFlv\mencoder\mencoder.exe"/>
    <add key="mplayer" value="D:\STUDY\dotnet项目\ToFlv\ToFlv\mencoder\mplayer.exe"/>
    <!--上传文件的路径-->
    <add key="upfile" value="D:\STUDY\dotnet项目\ToFlv\ToFlv\UpFiles"/>
    <!--上专文件图片路径-->
    <add key="imgfile" value="D:\STUDY\dotnet项目\ToFlv\ToFlv\ImgFile"/>
    <!--上传文件图片大小-->
    <add key="CatchFlvImgSize" value="240x180"/>
    <add key="widthSize" value="400"/>
    <add key="heightSize" value="350"/>
    <!--转换后文件路径-->
    <add key="playfile" value="D:\STUDY\dotnet项目\ToFlv\ToFlv\PlayFiles"/>
  </appSettings>
</configuration>

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace ToFlv
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnStart_Click(object sender, EventArgs e)
        {
            PublicMethod pm = new PublicMethod();
            try
            {
                pm.ChangeFilePhy(txtBefore.Text, txtAfter.Text, txtImg.Text);
                message.Text = "转换成功";
            }
            catch (Exception ex)
            {
                message.Text = ex.Message;
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string s = DateTime.Now.ToString("yyyyMMddHHmmssffff");
            txtAfter.Text = txtAfter.Text+"\\"+s;
            txtImg.Text = txtImg.Text + "\\" + s;
        }
    }
}